PROVEN EFFECTIVE STRATEGY

PREMIUM VALUE, DEFINED GROWTH, INDEPENDENT.

ARTIFICIAL LIFT CONFERENCE ESP DESIGN AND OPERATION

April 29 – 30, 2015

CNQ

‒ An ESP is not just artificial lift tool it is an acceleration tool. ‒ Need to be able to justify the incremental cost with incremental

production. ‒ Does the increase in production result in incremental reserves or

accelerated production?

Is an ESP appropriate?

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Pro’s Cons

Can land around corners in deviated/horizontal wells

Large pump so sensitive to dog leg severity

High capacity Major equipment downhole

Can vary speeds with VFD Need to know the well

CNQ

• Complex system which needs to be in balance ‒ IPR/PI – need to know reservoir information as accurately as possible ‒ Pump – uses the IPR/PI information in its design ‒ Motor – matched to both the pump and the reservoir fluid ‒ Cable – matched to the motor and the required load ‒ Isolating transformer – filters dirty power, helps extend run life ‒ VFD – conditions the power to allow the motor to run at different speeds ‒ Tubing – friction losses a function of length, size and roughness ‒ Surface facilities - all sources of pressure loss increase tubing head

pressure

Production System

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Production Profile

•  Production characteristics are important ‒ How lively is your oil? ‒ How high is the water cut? ‒  Is GOR going up?

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Well vs Pump

•  Need accurate production data

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• Pump design requires the most complete and accurate input information possible.

• The better the inputs, the better the design.

Typical Pump Design Data Requirements

Slide 6

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Typical Pump Curve

Slide 7

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Material Selection

•  Corrosion potential from H2S and CO2 can shorten life - H2S leads to hydrogen embrittlement - CO2 corrosive with water

•  Abrasives have a dramatic effect. •  Work with the supplier to choose the best materials. •  Consider stocking long lead time special material parts.

Slide 8

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Motor Selection

•  Depending where you are in the range a size up might be better. •  Bigger motor will run cooler. •  Might also future proof for changes in fluid gradient or rate.

Slide 9

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Power, the Mysterious Variable

•  Electric switchgear can be a major weakness.

•  Poor power quality is probably a major cause of premature failure.

•  Modern VFD’s have more built in power conditioning than vintage equipment.

•  Other loads on the power grid can affect your power quality.

•  Match your equipment.

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Cable Selection

•  Cable might seem like an accessory but is a major component visa vis cost.

•  Cable sizing important, power losses can be significant.

•  Cable failure at connections/splices or where it comes through the wellhead are common.

•  Round cable is better than flat due to current underbalances characteristic of flat cable.

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Running the Pump

•  You are about to lower $200,000 of equipment down the well •  Check rig, both equipment and personnel.

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Running Cable

•  Cable spooler controls speed and therefore tension.

•  Need a skilled hand to coordinate with rig.

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Rig Equipment

•  Make sure the running equipment is appropriate

•  Brief the crew on nuisances of running a pump with cable.

Slide 14

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Amp Chart

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Sensors

•  Sensor is not just to hold down the motor. •  If you are going to run it, use it. •  Ideally tied in to monitoring system.

Slide 16

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Listen to the Pump

•  Startup data from the pump. You have to be there to get it. •  This pump failed in less than 2 hours from startup. •  Everything seemed to be going well until motor temperature starts to rise. •  Pump failed on overcurrent, ie, got too hot. •  Note temp difference between operating and failure was 25oF, probably wouldn’t

have noticed it on surface.

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Generic Measurements

•  Validate sensor information to increase confidence.

•  Tubing temperature and pressure to confirm flow

•  Casing pressure and fluid level confirm pump submergence.

•  Compare bottom hole pressure calculated from fluid level/casing pressure to that from sensor. You might not like what you see.

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24/7 Monitoring

•  If you have enough pumps and dedication, around the clock monitoring and decision making can increase run time.

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Failure Analysis

•  Tear down the pump and see what failed. Remember, a bad O-ring brought down the Challenger.

•  Documentation of the results will eventually result in a meaningful database

•  Industry cooperation has built large databases but analysis is still tricky.

•  Part of the benefit is tracking of surplus inventory.

•  CNRL belongs to a group that collects data which can be reported in different ways.

•  Minimum data set 38 data points, recommended data set 128 data points.

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Random Points

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• Storing cable for more than a year is not a good idea. The insulation deteriorates due to absorbed gas devolving.

• Suppliers often reserve the right to substitute materials. It takes a sharp eye to avoid becoming part of their R&D.

•  Individual parts are relatively cheap, don’t avoid replacing a questionable component to “save money”.

•  If you spend the money on a downhole sensor, collect and use the data. If you can’t measure it you can’t manage it.

• Seek out a corporate expert. A lot of major producers have people on staff who have an incredible knowledge base and whose interests are aligned with yours, they are not trying to sell you anything.

PROVEN EFFECTIVE STRATEGY

PREMIUM VALUE, DEFINED GROWTH, INDEPENDENT.

THE PREMIUM VALUE, DEFINED GROWTH, INDEPENDENT.